1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* lib/crypto/raw/raw_aead.c
*
* Copyright 2008 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#include "crypto_int.h"
unsigned int
krb5int_raw_crypto_length(const struct krb5_keytypes *ktp,
krb5_cryptotype type)
{
switch (type) {
case KRB5_CRYPTO_TYPE_PADDING:
return ktp->enc->block_size;
default:
return 0;
}
}
krb5_error_code
krb5int_raw_encrypt(const struct krb5_keytypes *ktp, krb5_key key,
krb5_keyusage usage, const krb5_data *ivec,
krb5_crypto_iov *data, size_t num_data)
{
krb5_crypto_iov *padding;
size_t i;
unsigned int blocksize, plainlen = 0, padsize = 0;
blocksize = ktp->crypto_length(ktp, KRB5_CRYPTO_TYPE_PADDING);
for (i = 0; i < num_data; i++) {
krb5_crypto_iov *iov = &data[i];
if (iov->flags == KRB5_CRYPTO_TYPE_DATA)
plainlen += iov->data.length;
}
if (blocksize != 0) {
/* Check that the input data is correctly padded */
if (plainlen % blocksize)
padsize = blocksize - (plainlen % blocksize);
}
padding = krb5int_c_locate_iov(data, num_data, KRB5_CRYPTO_TYPE_PADDING);
if (padsize && (padding == NULL || padding->data.length < padsize))
return KRB5_BAD_MSIZE;
if (padding != NULL) {
memset(padding->data.data, 0, padsize);
padding->data.length = padsize;
}
return ktp->enc->encrypt(key, ivec, data, num_data);
}
krb5_error_code
krb5int_raw_decrypt(const struct krb5_keytypes *ktp, krb5_key key,
krb5_keyusage usage, const krb5_data *ivec,
krb5_crypto_iov *data, size_t num_data)
{
size_t i;
unsigned int blocksize = 0; /* enc block size, not confounder len */
unsigned int cipherlen = 0;
/* E(Confounder | Plaintext | Pad) | Checksum */
blocksize = ktp->crypto_length(ktp, KRB5_CRYPTO_TYPE_PADDING);
for (i = 0; i < num_data; i++) {
const krb5_crypto_iov *iov = &data[i];
if (ENCRYPT_DATA_IOV(iov))
cipherlen += iov->data.length;
}
if (blocksize == 0) {
/* Check for correct input length in CTS mode */
if (ktp->enc->block_size != 0 && cipherlen < ktp->enc->block_size)
return KRB5_BAD_MSIZE;
} else {
/* Check that the input data is correctly padded */
if (cipherlen % blocksize != 0)
return KRB5_BAD_MSIZE;
}
return ktp->enc->decrypt(key, ivec, data, num_data);
}
|
